Graphics card Problem *crys*

[Adie789]

Graphics card issues

Ok so ive just recently done a custom build with some help from this forum on the hardware to choose now since ive had serious problems with my graphics card. Running a 8800GTX and all ive been getting is hard lockups and freezing problems i know its a known issue as ive been searching for answers but to no avail.
At one point i was running windows vista and all i was getting was the above freezing/lockups but with the BSOD and that was apparently due to the drivers not being out. Since i decided to go back onto xp and im still having issues i really dont know what to do next im here as a last resort. Please help

Computer Specs -

http://img391.imageshack.us/img391/7614/compnq7.jpg

Intel Core 2 DUO E6600 "LGA775 Conroe" 2.40GHz
Asus P5N-E SLi nForce 650 (Socket 775) PCI-Express DDR2 Motherboard
Corsair 2GB DDR2 XMS2-6400C4 TwinX (2x1GB)
Gainward BLISS GeForce 8800 GTX 768MB GDDR3 HDTV/Dual DVI (PCI-Express) - Retail
Seagate Barracuda 7200.10 250GB ST3250620AS SATA-II 16MB Cache -
Sony AW-G170AB2 18x DVD±RW x12 Ram Dual Layer DVD-Writer - (Black) OEM
Tuniq Tower 120 CPU Cooler
Seasonic M12 Modular 600W Silent ATX2.0 Power Supply
Antec Nine Hundred Ultimate Gaming case

 

[Adie789]

Sorry for the newbish question im fairly new at this how do i go about doing the above ive found memtest thats pretty simple were can i find the rest of the diagnostic tools i somone can point me in the right direction that be much appreciated.